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Date:   Thu, 21 Oct 2021 17:43:06 +0200
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Subject: Re: [RFC 06/16] KVM: selftests: add library for creating/interacting
 with SEV guests
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To:     Michael Roth <michael.roth@amd.com>, Marc Orr <marcorr@google.com>
Cc:     linux-kselftest@vger.kernel.org, kvm list <kvm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>,
        Nathan Tempelman <natet@google.com>,
        Steve Rutherford <srutherford@google.com>,
        Sean Christopherson <seanjc@google.com>,
        Mingwei Zhang <mizhang@google.com>,
        Brijesh Singh <brijesh.singh@amd.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Varad Gautam <varad.gautam@suse.com>,
        Shuah Khan <shuah@kernel.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Ricardo Koller <ricarkol@google.com>,
        Jim Mattson <jmattson@google.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Joerg Roedel <joro@8bytes.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>
References: <20211005234459.430873-1-michael.roth@amd.com>
 <20211006203710.13326-1-michael.roth@amd.com>
 <CAA03e5EmnbpKOwfNJUV7fog-7UpJJNpu7mQYmCODpk=tYfXxig@mail.gmail.com>
 <20211012011537.q7dwebcistxddyyj@amd.com>
 <20211012125536.qpewvk6cou3mxya7@amd.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
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On 12/10/21 14:55, Michael Roth wrote:
> One more I should mention:
> 
> 4) After encryption, the page table is no longer usable for translations by
>     stuff like addr_gva2gpa(), so tests would either need to be
>     audited/updated to do these translations upfront and only rely on
>     cached/stored values thereafter, or perhaps a "shadow" copy could be
>     maintained by kvm_util so the translations will continue to work
>     after encryption.

Yeah, this is a big one.  Considering that a lot of the selftests are 
for specific bugs, the benefit in running them with SEV is relatively 
low.  That said, there could be some simple tests where it makes sense, 
so it'd be nice to plan a little ahead so that it isn't _too_ difficult.

Paolo